Textile printing process and printing paste therefor



Patented Nov. 23, 1937 UNITED STATES r' 'r Nr OFFICE TEXTILE r'nm'rmc rnocuss AND ram'rmc PASTE rnnnurop I No Drawing. Application July 9, 1935, Serial July 26, 1934 In Germany and Great Britain 4 Claims. (01. 8-20) This invention relates to a textile printing process and a'printing-paste therefor. It is more particularly directed to a process for printing cotton or other cellulose-containing fabric with a paste containing a thiocyanate.

The action of calcium thiocyanate for printing on cotton and rayons is known. The thiocyanate has a. parchmentizingefiect on the fabric under the simultaneous action of heat and moisture so that where the thiocyanate acts on the fabric it produces greater transparency. Great difliculty has been experienced in attempts to use this process because of the fact that the thickened cal-' cium thiocyanate printing mass must be maintained in heated condition during use and the heat must be suitably regulated to prevent the mass from stiffening. At ordinary room temperature, say F. or somewhat above, the printing masses heretofore employed stiffened or jelled and were not suitable for printing.

I have now found in accordance with my invention that the jellying of the combination of a thiocyanate, water and a thickener which would ordinarily act on one another to cause a jelly to form' at low temperatures, can be avoided by the presence of an aliphatic aldehyde such as form aldehyde. By the use of the combination just mentioned a printing-paste which can be printed cold without difficulty is obtained. The mass has a better viscosity for penetration of the fibers of the fabric than the heated printing-paste heretofore employed. It accordingly better penetrates the fibers. I have found also that by addition of formaldehyde to this printing mass that the swelling action of the calcium thiocyanate is increased.

As thickeners I have found that both. starch and cellulose which are well-known as thickeners may be employed. Other thickeners can also be used for example cellulose derivatives. I prefer to employ reprecipitated cellulose as for instance viscose waste and have found such reprecipitated cellulose exceptionally suitable as a thickening agent. 1

My process can be applied to all kinds of cellulose-containing fabrics such as fiat fabrics, knit goods, braided goods, embroideries and the like. Fabrics may be employed which contain yarns of different fiber materials as for instance mixed fabrics or fabrics made from mixed yarns. Of

the artificial fiber materials those of reprecipitated cellulose and those produced from cellulose esters are suitable. The expression cellulosecontaining fabrics is intended to cover such fabrics of artificial or natural fibers or mixtures thereof.

The fabrics prior to the printing with the thiocyanate printing-paste may be pretreated in any desired manner. For example they may be boiled, halfor full-bleached or mercerlzed.

After the printing of my improved paste the fabrics are dried and thereupon I ordinarily develop the effect in the case of cotton or similar natural fiber by steaming or passing through a concentrated hot salt solution such as calcium chloride at a temperature above C. After this treatment the fabrics are Washed and dried. Artificial silk fabrics as a rule do not require any steaming or calcium chloride process but can be washed directly after the drying of the printing.

For. certain kinds of fabrics, viz. cotton-mousseline, -satin, -voile, subsequent mercerization can be applied under tensioning. Intensification of Examples 1. Bleached, mercerized, cotton mousseline fabric is printed at about 18 C. with the following mass:

Giams Calcium thiocyanate crystallized 710- Water 106 Viscose waste 22 Formaldehyde concentrated technical (in- & dustrial) formaldehyde content about The fabric is well dried in the 10s; at about 5 80 C. and thereupon immediately passed through A a developing bath of the following composition:

Parts by weight Calcium chloride, granulatedn 3 Water- The temperature of this bath is kept at C. The time of action is about 15 seconds; after this passage the fabric is washed cold, cenl l llged, finished and dried.

2. A viscose fabric is printed at about 18 c. with the following mass:

Grams Calcium thiocyanate crystalized 650 5 Water 170 Viscose waste 18 Formaldehyde concentrated technical (industrial) formaldehyde content abou 40% v 162 following mass:

Calcium thiocyanate crystalized Water Formaldehyde concentrated t e c h n i c a l (40 Wheat starch After the mass is printed, the fabric is dried, rinsed with-cold water and then dried on a tenter frame. 1

'5. A cotton mousseline fabric as used in Example 1 is printed with the following mass:

Grams Calcium thiocyanate crystalized 700 Water 100 Acetate silk waste Formaldehyde concentrated technical The further treatment is done as in Example 1. Thevlscose waste mentioned in the above examples consists of viscose silk out in short staples. Other reprecipitated cellulose may be em- 6. A viscose voile fabric is printed with the Grams ployed if desired. Other salts or agents than calcium chloride may be employed in the development bath. Calcium chloride is representative of an inexpensive compound which will raise the temperature of the bath to about 115120 C. and

effect the desired development.

The result of the above printing is to produce a fabric having relatively transparent portions on aless transparent background. These effects as noted above may be combined with other effects produced by mercerization, shrinkage, etc.

The expression room temperature as employed in the claims and elsewhere herein is intended to designate a temperature of about 18 C. (about F.) or temperatures somewhat above or below that point.

I claim:

1. A process for printing cellulosic fabrics or the like which comprises combining calcium thiocyanate, water and a thickener consisting of reprecipitated cellulose which would ordinarily act on one another to produce a jelly at room temperature and also combining therewith a sufficient quantity of formaldehyde to oppose such jellying action to produce a paste for printing on cellulose fabrics and printing such paste on a cellulose fabric at room temperature.

2. A step in the process of printing cellulosic fabrics which comprises treating a cellulose fabric at low temperature with a combination of a thiocyanate, water and a thickener which would ordinarily act on one another to produce a jelly at room temperature, and formaldehyde to oppose such jellying.

3. A process for printing which comprises printing a cotton fabric at low temperature with a combination of calcium thiocyanate, water and a reprecipitated cellulose as a thickener which would ordinarily act on one another to produce a jelly at room temperature, in the presence of formaldehyde to oppose such jellying, and de-' veloping such printing above C. in a salt bath containing sufficient salt to raise the boiling temperature of the bath above said last mentioned temperature.

4. A printing-paste containing calcium thiocyanate, water and viscose waste which would ordinarily act on one another to produce a jelly at room temperature and formaldehyde to preventjellying of paste at such temperature.

ERNST WEISS. 

